Combined typewriting and computing machine



April 14, 1931- H. o. BLAISDELL 1,800,197

COMBINED TYPEWRITING AND COMPUTING MACHINE Filed July 3- 192 Patented Apr. 14, 1931' UNITED STATES PATENT OFFICE HARRISON O. BLAISDELL, 0F BROOKLYN, YORK, A SSIGNOR, BY MESNE ASSIGN- MENTS; TO ELLIOTT-FISHER COMPANY, OF NEW YORK, N. Y., A CORPORATION OF DELAWARE comamnn ryrrrwarrrna AND comrurnte macrrmn I Application filed July 3,1926. Serial Ito; 180,888.

This invention relates to a combined typewriting and computing machine, and isill-ustratedas applied to a machine of the Underwood-Hanson type, such as shown in the 3 patents to Hans Hanson, No, 1,278,812, dated September 10, 1918, Ogden Minton, No. 1,280,065, dated September 24, 1918, and others.

Each dial-wheel of each register is asso- 10 ciated'with a computing bar set by means of the numeral-keys of the typewriter. The computing bars are moved from idle to setting positions in denominational order, by means associated with .the carriage of the typewriter; and finally a general operator rotates the dial-wheels in accordance with the numeral-keys which have been depressed.

The machine is automatically set when the carriage moves into predetermined zones, to either add or subtract. The machine has. a 'bichrome ribbon, a red stripe usually indicating subtraction while a black stripe'indicates addition. Under certain conditions, especially when typing amounts indicating a debit balance, it may be desired to subtract amounts from the register to clear it and to type the, amount in black.

In some systems of bookkeeping in which twin forms are used, the forms are designed so that amounts typed in a column upon one form are additively entered into a register, while the amounts typed in a corresponding column of the other form are subtractively entered into the same register, Heretofore, in order to change the machine from addition to subtraction in a certain zone, it .was customary to take out one of the tabulating stops and to replace it witha different kind of a stop. In doing this it was easy to misplace the stops in relation to the column of thework sheet, resulting in shifting the .figures in the same column relatively to each other. According to certain features of this invention, there is provided a special stop which can be used either to obtain black addition or black subtraction in the same column. The stop is provided with aswinging plate which can be thrown to either effective or ineffective position without disturbing the Figure 2 is a similar view, showing the plate swung in its ineffective position, the

machine being normally set for black addition.

Figure 3 is a diagrammaticyiew, showing the ribbon-shifting mechanism of an Underwoodtypewriting machine set for indicating the field or" the ribbon for a black subtraction.

Figureis a perspective view of the camplate associated with the tabulating stop.

Figure 5 is a side view of the tabulating stop, showing the cam-plate in its efi'ective' black subtraction position in full lines, and in its inefiective or black addition position in dot-and-dash lines.

a Figure '6 is a cross-sectional view through line 6--6 of Figure 5 on an enlarged scale.

provided with a carriage 10, upon which a platen 11 is revolubly mounted by means of a shaft 12. The platen serves as ameans for receiving the blows of type-bars 13, which are .operatively connected to'character and numeral keys, not shown. At the rear of the carriage thereis rovided'a cross-bar 14 having teeth 15, which serve as a means for 10- cating and locking tabulating stops 16. Said tabulating'stops move with the carriage, and serve as ameans for arresting the same when tabulating keys, not shown, release the carriage and raise tabulating plungers 17 in the path of the stops, to thereby position the carriage fora redeterminedcolumn of the work-sheet. T e lungers 17 engage with the lower edge 18 0 one of two side plates 19, which enter the teeth 15 and positively-locate the stop.

Said edge 18 is also effective to automatically trip the motor after having typed a number upon the work-sheet. To this end, the

The Underwood computing machine is Iss machine is provided with 'a lever 20, rockably mounted upon .a stud 21, the lever fbeing swung when the edge- 18 engages with a one:

way pawl 22 carried by the lever. Av link'23 is pivotally mounted upon one end of the lever 20 in a manner to draw the link upwardly when the lever is swung. Said link 23"is operatively connected at the other end theref of to a bell-crank 24 'pivotally mounted on fast upon a shaft 29, when urged upwardly by a spring 30. Said spring is strong enoughto move a slide 31, which engages by means of afpin 32 a rear extension 33 of the arm 28. The lower end of the slide 31 engages one end of a rockerarm 34, borne by a pivot-pin 35, in amanner to raise the other end thereof, tothereby move therewith a plunger-pin 36,

which is withdrawn from the path of a lug 37 carried by a disk 38 mountedon a driving mechanism, not shown, but efiective toreciprocate a general operator 39.

When the carriage reachesapredetermined' .posltion, 1t is sometimes deslrable to auto matically shift the computing mechanism to subtraction. This shifting is controlled by means of atappet preferably-in the form of a projecting shoe or cam plate 40, pivotally mounted at one end upon a stud 41, which serves also as a means for holding and spac-- ingthe side plates 19: The cam-plate 40 engages-a one-way pawl 42, carried bya lever 43m'ounted on the stud 21 in a manner to rock thew-lever and elevate one end thereof, upon which a link 43 is pivotally mounted. The

.- link 43 extends downwardly, and is connected at its lowermost end to a bell-crank 44, .pivotally mounted-upon the shaft 25. Said bell-crank44 is provided with a link 45, pivotally mounted thereon, which link is withdrawn from'under a lever '46 when the b6117- crank is swung by the action of the link 43.

The lever46 is fast to a cross-shaft 47, which carries fast thereto a pawl 48 designed to engage in a notch 49, and thereby retain a subtraction-setting bar-50 in its normal or ineffective position, as shown in Figure 1. The withdrawal of the link from under the lever 46 has the effect of releasingaspring 46, normally held under tension, and thereby rocking the shaft47. Obviously, when rocking the shaft, the pawl 48 will disengage the notch 49, thereby permitting a spring 51 to retract the bar to its subtracting position.

' The bar 50 is effective to set the mechanism for subtraction in a manner such as disclosed in said patent to Minton.

In order that the operative may be aware .of the character of the computation which takes place, there is provided indicating mechanism, which not only indicates whether the amount is to be added or subtracted, but also the color in which the amount will be tfiped upon theWork-sheet' To thisend,

ere are provided two swinging arms 52 and 53, the latter, which indicates the ribbonfield, being fast to a rock-shaft 54. The arm 52 is operatively connected, by means of a;

link 55 and anarm 56, to a downwardlyextending link 57, which is supported at its lower end by means ofv a bracket 58. Saidlink 57 is in line with a plunger 59, "slidably mounted in. a bracket 60 andcarrfedby an arm 61 fast to a rock-shaft 62, which in turn is connected to the bar 50 bymeans of a-lever 63 which engages a pin 64 on the bar 50. Wien the bar, 50 moves rearwardly, the plunger engages the lower end of the link,

thereby swinging the arm 53 to indicate subtraction, as shown in Figure 3.

ormally, when themachine is set for subtraction, a bichrome ribbon 65 is vibrated in its lower field, so that the typing may appear in red, thereby indicating that the amount has been subtracted. The ribbonis automatically set to print in its black or upper field when the machine is reset for addi. tion. In order to control the shifting of the rlbbon to correspond with the character of the computation, there are provided mechanism 66 for vibrating the ribbon, and means including an arm 67 and'a link 68 for operatively connecting the rock-shaft 54 to the ribbon-vibrating mechanism 66. It will be seen by an inspection of Figure 1 that the 'plunger59, when moved upwardly, not only engages the link 57, but also a pendant or link 69, operatively connected to an arm 70 fast to the rock-shaft 54.

Sometimes, especially when typing a debit balance, it is desired to subtract therefrom the amount shown to clear the register, and toprint the amount in black, so as to differautom'atically bring about this condition, when the carriage enters a predetermined computing zone, the cam plate 40 may be" made wide enough to permit one side thereof thependant 69 may be rendered ineffective at will, thereb preventing the shifting of. the ribbon, alt ough he machine is set for subtraction.

.110 entiate it 'fro1n credit balances on the same sheet, which are typed in red. In order to i respectively in Figures 1 and 2, and that the The two thin side plates 19 of the tappet are spaced apart by "shouldered studs, as 41 and 82, the ends of the studs being upset on the outside of the plates to bind the plates against the shoulders of the studs in a wellknownmanner. For the purpose of-the present invention, one of the studs, as 41, may have an intermediate shoulder formed by a reduced bearing-surface which enters a hole 86 in an arm 87 formed by bending over one end of the cam-plate 40 at right angles. The arm 87 may be assembledupon the rivet 41 during the assembly of the plates 19 and provide for a free swinging movement of the cam-plate 40 confined between the inner face of one side plate 19 and the shonlder of the rivet. 5 As it is desirable that the cam-plate 40 shall be semi-locked in the operative position of Figure 1, and also held in the inoperative position of Figure 2, the arm 87 may be provided with a stud 81 permanently riveted to the inner face, of said arm to stand parallel to the plane of the cam-plate 40. The stud may have a central blind hole to enclose a compression spring 80 and a detent-ball 78, the edges of the hole after the assembly of spring and ball therein being sli htly upset to retain the ball as a pre-assemb ed'unit before the plate 40 is assembled upon the rivet 41. The assembly of the plate 40 upon the rivet 41 compresses the spring 80 by forcing the assembled ball 78 into the stud 81, said ball thereafter being under tension against the inner face of the/adjacent side plate 19.

To coact with the ball 78,-the adjacent plate 19 may have two holes 79 radial with the rivet 41 and at positionsto time the location of the ball 78 for the two positions of the cam-plate in Figures land 2, the inner edges of the holes 79 being chamfered to form suitable cam-plate-holding seats for the ball.

To co-operate with the ball 78and prevent overthrow of the plate 40 at the 'end of either of its two manually shifted positions, the arm- 87 is formed to strike the rivet 82 in one direction of its swing. To this end, the free end 88 of the arm 87 ma. be cut away to strike a reduced section 83 of the rivet 82 to align the plate-40 in its computing-control position, and the edge 89 of said plate 40 may strike the largefdiameter of the stud 82 in the inoperative stop position of the plate 40, as indicated in broken lines in Figure 5.

It "will be understood that thecaIn-plate may be rendered either eflz'ective or ineffective by simply swinging it to the positions shown cam-plate may be again restored to its former position without necessitating the replacement of the stop. It will be also understood that although the mechanism which reciprocates the general operator will be tripped by engagement with the edge 18 of the plate 19,

no harm will result thereby, even though this atabulating and computing rack, said unit I being a column-stop provided with shiftable means for converting it, into a combined column-stop and subtraction-setting stop.

2. A tappet-unit formed for attachment to a tabulating and computing rack, said unit being a column-stop provided with shiftable means, for converting it into a combined column-stop and subtraction-setting stop, said tappet-unit including a thin stop-plate engageable within any slot in the tabulating rack to determine a computing-zone position,

and a normally inoperative subtraction-setting plate rockably mounted upon the stop:

plate to determine a subtractive state for a computing mechanism.

3. A tappet-unit formed for attachment to a tabulating and computing rack, said unit being a column-stop provided with shiftable means for converting itinto a combined column-stop and subtraction-setting stop, said tappet-unit including a pair of thin side plates spaced apart by rivets, so that the plates may enter adjacent slots of the tabulating rack to establish a computing zone, and a normall inoperative subtraction-setting ,plate roc ably mounted between the plates upon one rivet and'formed-with an arm to engage another rivet for a stop-setting position, effective to change a normal state of a computing mechanism to a subtractive state.

uponone spacing rivet and between the plates to engage alternate sides of another spacing rivet to determine a computative state for a computing mechanism.

5. Atappet-unit formed for attachment to a tabulating and computing rack, said unit.

being a column-stop provided with shiftable means for convertingit into a combined column-stop and subtraction-settingstop, said tappet-unit including a pair of thin plates held together by spacing rivets and each plate engageable between spaced-apart teeth of the tabulating rack, and means rockably 4. A tappet-unit formed for attachment to 'mounted'up'onjone of the rivets and between the plates, operable at will to be swung between stop positions on the tappet and deter mine a computative v state for a computing 5 mechanism within a column simultaneously predetermined by the tappet.

6. A tappet-un'it formed for attachment to a tabulating and computing rack, said unit being a column-stop providedwith shiftable 10 means for converting it into a combined col umn-stop and subtraction-setting stop, said tappet-unit including a pair of thin plates joined together by a pair of spacing rivets to engage adjacent slots in the tabulating rack,

15 and a subtraction-setting plate disposed at right angles toethe pair of plates and assem'bled between them upon one rivet, said subtraction-setting plate in swingably engaging the other rivet in two directions de- 20 termining the operative and inoperative positions for said subtraction-Setting plate relative to a computing mechanism Within a computing zone simultaneously established by the tappet. I

-' HARRISON O; BLAISDELL. 

